The present invention is concerned with novel broad-spectrum azole antifungals and their preparation; it further relates to compositions comprising them, as well as their use as a medicine.
Systemic fungal infections in man are relatively rare in temperate countries and many of the fungi that can become pathogenic normally live commensally in the body or are common in the environment. However, the past few decades have witnessed an increasing incidence of numerous life-threatening systemic fungal infections world-wide and these now represent a major threat to many susceptible patients, particularly those already hospitalized. Most of the increase can be attributed to improved survival of immunocompromised patients and the chronic use of antimicrobial agents. Moreover, the flora typical of many common fungal infections is also changing and this is presenting an epidemiological challenge of increasing importance. Patients at greatest risk include those with impaired immune functioning, either directly as a result of immunosuppression from cytotoxic drugs or HIV infection, or secondary to other debilitating diseases such as cancer, acute leukaemia, invasive surgical techniques or prolonged exposure to antimicrobial agents. The most common systemic fungal infections in man are candidosis, aspergillosis, histoplasmosis, coccidioidomycosis, paracoccidioidomycosis, blastomycosis and cryptococcosis.
Antifungals such as ketoconazole, itraconazole and fluconazole are employed for the treatment and prophylaxis of systemic fungal infections in immunocompromised patients. However, concern is growing about fungal resistance to some of these agents, especially these with a more narrow spectrum, e.g. fluconazole. Worse still, it is recognized in the medical world that about 40% of the people suffering from severe systemic fungal infections are hardly, or not at all, able to receive medication via oral administration. This inability is due to the fact that such patients are in coma or suffer from severe gastroparesis. Hence the use of insoluble or sparingly soluble antifungals such as itraconazole, that are difficult to administer intravenously, is heavily impeded in said group of patients.
Consequently, there is a need for new antifungals, preferably broad-spectrum antifungals, against which there is no existing resistance and which can be administered intravenously. Preferably the antifungal should also be available in a pharmaceutical composition suitable for oral administration. This enables the physician to continue treatment with the same drug after the patient has recovered from the condition which required intravenous administration of said drug.
U.S. Pat. No. 4,267,179 discloses heterocyclic derivatives of (4-phenylpiperazin-1-yl-aryloxy-methyl-1,3-dioxolan-2-yl)-methyl-1H-imidazoles and 1H-1,2,4-triazoles useful as antifungal agents. Said patent encompasses itraconazole, which is now available as a broadspectrum antifungal on a world-wide basis.
U.S. Pat. No. 4,916,134 teaches 4-[4-[4-[[2-(2,4-difluorophenyl)-2-(1H-azolylmethyl)-1,3-dioxolan-4-yl]methoxy]phenyl]-1-piperazinyl]phenyl]triazolones having improved antimicrobial properties.
U.S. Pat. No. 4,791,111 discloses derivatives of [[4-[4-(4-phenyl-1-piperazinyl)phenoxymethyl]-1,3-dioxolan-2-yl]methyl]-1H-imidazoles and 1H-1,2,4-triazoles, structurally related to some of the compounds of the present invention, which are taught to have favourable anti-microbial properties. A particular compound disclosed herein is cis-4-[4-[4-[4-[[2-(2,4-difluorophenyl)-2-(1H-1,2,4-triazol-1-ylmethyl)-1,3-dioxolan-4-yl]-methoxy]-phenyl]-1-piperazinyl]phenyl]-2,4-dihydro-2-(2-hydroxy-1-methylpropyl)-3H-1,2,4-triazol-3-one, said compound being a stereoisomeric mixture of all possible enantiomers and diastereomers having the cis configuration at the 1,3-dioxolane ring. WO 93/19061 discloses the [2R-[2xcex1,4xcex1,4(R*)]], [2R-[2xcex1,4xcex1,4(S*)]], [2S-[2xcex1,4xcex1,4(S*)]] and [2S-[2xcex1,4xcex1,4(R*)]] stereospecific isomers of itraconazole, which are taught to have greater water solubility than the respective diastereomeric mixtures thereof.
WO 95/19983 discloses derivatives of [[4-[4-(4-phenyl-1-piperazinyl)phenoxy-methyl]-1,3-dioxolan-2-yl]methyl]-1H-imidazoles and 1H-1,2,4-triazoles, structurally related to some of the compounds of the present invention, which are taught to be water-soluble antimicrobial agents.
WO 95/17407 discloses tetrahydrofuran antifungals as well as WO 96/38443 and WO 97/00255. The latter two publications discloses tetrahydrofuran antifungals, which are taught to be soluble and/or suspendible in an aqueous medium suitable for IV, containing substitution groups readily convertible in vivo into hydroxy groups.
The present invention concerns novel compounds of formula 
the N-oxide forms, the pharmaceutically acceptable addition salts and stereochemically isomeric forms thereof, wherein xe2x80x94Axe2x80x94Bxe2x80x94 forms a bivalent radical of formula:
xe2x80x94Nxe2x95x90CHxe2x80x94xe2x80x83xe2x80x83(a),
xe2x80x94CHxe2x95x90Nxe2x80x94xe2x80x83xe2x80x83(b),
xe2x80x94CHxe2x95x90CHxe2x80x94xe2x80x83xe2x80x83(c),
xe2x80x83wherein one hydrogen atom in the radicals (a) and (b) may be replaced with a C1-6alkyl-radical and up to two hydrogen atoms in radical (c) may be replaced by a C1-6alkyl-radical;
L represents the acyl moiety of an amino acid, and thus xe2x80x94Oxe2x80x94L represents an amino acid ester group;
D is a radical of formula 
xe2x80x83wherein
X is N or CH;
R1 is halo;
R2 is hydrogen or halo.
In the definitions hereinabove and hereinafter the term halo defines fluoro, chloro, bromo and iodo; C1-6alkyl is generic to straight and branch chained hydrocarbons having from 1 to 6 carbon atoms, such as, for example, methyl, ethyl, propyl, butyl, pentyl or hexyl and the possible branched isomers thereof.
In the definition of L, the term xe2x80x9camino acidxe2x80x9d is meant to include, but not limited to,
the 20 xcex1-amino acids commonly found in proteins such as, glycine, alanine, valine, leucine, isoleucine, methionine, proline, phenylalanine, tryptophan, serine, threonine, cysteine, tyrosine, asparagine, glutamine, aspartic acid, glutamic acid, lysine, arginine and histidine; and,
amino acids of relatively rare occurrence which have been identified in specialized types of proteins such as, for example, 4-hydroxyproline, hydroxylysine, desmosine and isodesmosine; and,
over 150 other amino acids occuring biologically in free or combined form but never in proteins whether they are xcex1-, xcex2-, xcex3- and xcex4-amino acids or whether they have a L-or D-configuration such as, for example, xcex2-alanine, homocysteine and homoserine, citrulline, ornithine, xcex3-aminobutyric acid, D-glutamic acid and D-alanine; and
synthetic amino acid analogues, such as, for example, phenylglycine, p-fluorophenylalanine, thionine, norleucine and the like.
In the definition of L, the term xe2x80x9camino acidxe2x80x9d is also meant to include those amino acids in which the amino moiety is mono- or disubstituted; in such instances L may be represented by xe2x80x94Lxe2x80x2xe2x80x94NRxRy. Examples of Rx and Ry include hydrogen, C1-6alkyl and art-known protective groups for the amino moiety, e.g. tert-butyloxycarbonyl, benzyloxycarbonyl, trifluoromethoxycarbonyl or those protective groups mentioned in Chapter 7 of xe2x80x9cProtective Groups in Organic Synthesisxe2x80x9d by T. Greene and P. Wuyts (John Wiley and Sons, Inc. 1991). Rx and Ry may also form together with the nitrogen atom of the amino moiety of the amino acid a ring such as, for example, a pyrrolidine, piperidine, morpholine, piperazine or substituted piperazine ring, said substituted piperazine being a piperazine ring substituted on the 4-position of the piperazine ring with, for instance, C1-6alkyl, hydroxyC1-6alkyl, aminoC1-6alkyl, mono- or di(C1-6alkyl)aminoC1-6alkyl.
For instance, in the case L is the acyl moiety of N,N-diethylglycine, then Lxe2x80x2xe2x80x94 represents xe2x80x94C(xe2x95x90O)xe2x80x94CH2xe2x80x94 and xe2x80x94NRxRy represents xe2x80x94N(CH2CH3)2.
Many amino acids are commercially available and are listed in Novabiochem""s 1997/1998 Catalog and Peptide Synthesis Handbook (Calbiochem-Novabiochem AG, Lxc3xa4ufelfingen, Switzerland). Also these commercially available amino acids are meant to be included in the term xe2x80x9camino acidxe2x80x9d as used in the definition of L.
The pharmaceutically acceptable addition salts as mentioned hereinabove are meant to comprise the therapeutically active non-toxic acid addition salt forms which the compounds of formula (I) are able to form. The latter can conveniently be obtained by treating the base form with such appropriate acids as inorganic acids, for example, hydrohalic acids, e.g. hydrochloric, hydrobromic and the like; sulfuric acid; nitric acid; phosphoric acid and the like; or organic acids, for example, acetic, propanoic, hydroxy-acetic, 2-hydroxypropanoic, 2-oxopropanoic, oxalic, malonic, succinic, maleic, fumaric, malic, tartaric, 2-hydroxy-1,2,3-propanetricarboxylic, methanesulfonic, ethanesulfonic, benzenesulfonic, 4-methylbenzenesulfonic, cyclohexanesulfamic, 2-hydroxybenzoic, 4-amino-2-hydroxybenzoic and the like acids. Conversely the salt form can be converted by treatment with alkali into the free base form.
The compounds of formula (I) containing acidic protons may be converted into their therapeutically active non-toxic metal or amine addition salt forms by treatment with appropriate organic and inorganic bases. Appropriate base salt forms comprise, for example, the ammonium salts, the alkali and earth alkaline metal salts, e.g. the lithium, sodium, potassium, magnesium, calcium salts and the like, salts with organic bases, e.g. the benzathine, N-methyl-D-glucamine, 2-amino-2-(hydroxymethyl)-1,3-propanediol, hydrabamine salts, and salts with amino acids such as, for example, arginine, lysine and the like. Conversely the salt form can be converted by treatment with acid into the free acid form.
The term addition salt also comprises the hydrates and solvent addition forms which the compounds of formula (I) are able to form. Examples of such forms are e.g. hydrates, alcoholates and the like.
Suitable salt forms of the present compounds include the fumaric-, succinic-, L-malic-, oxalic-, maleic-, L-tartaric and hydrochloric acid salt form as well as the hydrated forms.
The term xe2x80x9cstereochemically isomeric formsxe2x80x9d as used hereinbefore defines all the possible stereoisomeric forms in which the compounds of formula (I) may exist, thus, also including all enantiomers, enantiomeric mixtures and diastereomeric mixtures. Unless otherwise mentioned or indicated, the chemical designation of compounds denotes the mixture of all possible stereochemically isomeric forms, said mixtures containing all diastereomers and enantiomers of the basic molecular structure. The same applies to the intermediates as described herein, used to prepare endproducts of formula (I).
Pure enantiomerically forms of the compounds and intermediates as mentioned herein are defined as enantiomers substantially free of other enantiomeric or diastereomeric forms of the same basic molecular structure of said compounds or intermediates.
Asymmetric centers may have the R- or S-configuration. The terms cis and trans are used herein in accordance with Chemical Abstracts nomenclature and refer to the position of the substituents on a ring moiety, more in particular on the dioxolane ring in the compounds of formula (I). In the latter instance, when establishing the cis or trans configuration, the substituent with the highest priority on the carbon atom in the 2 position of the dioxolane ring, and the substituent with the highest priority on the carbon atom in the 4 position of the dioxolane ring are considered (the priority of a substituent being determined according to the Cahn-Ingold-Prelog sequence rules). When said two substituents with highest priority are at the same side of the ring then the configuration is designated cis, if not, the configuration is designated trans.
The compounds of formula (I) all contain at least 4 asymmetric centers. As used herein, the stereochemical descriptors denoting the stereochemical configuration of each of the 4 or more asymmetric centers are also in accordance with Chemical Abstracts nomenclature. For instance, the absolute configuration of the asymmetric carbon atoms of compound 23 as described in example B.2 hereinafter, i.e. [2S-[2xcex1,4xcex1[(R*,R*)]]]-2-[4-[4-[4-[4-[[2-(2,4-difluorophenyl)-2-(1H-1,2,4-triazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]-phenyl]-1-piperazinyl]-phenyl]-4,5-dihydro-5-oxo-1H-1,2,4-triazol-1-yl]-1-methylpropyl L-phenylalanine, is as depicted hereinbelow. The dioxolane ring in this compound has the cis configuration. 
Further in accordance with Chemical Abstracts nomenclature, the name of a radical followed by the name of an amino acid refers to an ester wherein the amino acid is the acyl group. For example, in compound 23, L-phenylalanine is esterified with the said substituted 1-methylpropyl group.
The same Chemical Abstracts nomenclature is used to designate enantiomeric mixtures. For instance, the descriptor of intermediate 2i, i.e. [2xcex1,4xcex1(R*,R*)] indicates that intermediate 2i is a mixture of two enantiomers having respectively [2S-[2xcex1,4xcex1(R*,R*)]] and [2R-[2xcex1,4xcex1a(R*,R*)]] as stereochemical descriptor.
Ring numbering on the dioxolane ring according to the Chemical Abstracts nomenclature is given for radicals D1 and D2 just below. 
Of some compounds of formula (I) and of intermediates used in their preparation, the absolute stereochemical configuration was not experimentally determined. In those cases the stereochemically isomeric form which was first isolated is designated as xe2x80x9cAxe2x80x9d and the second as xe2x80x9cBxe2x80x9d, without further reference to the actual stereochemical configuration. However, said xe2x80x9cAxe2x80x9d and xe2x80x9cBxe2x80x9d isomeric forms can be unambiguously characterized by for instance their optical rotation in case xe2x80x9cAxe2x80x9d and xe2x80x9cBxe2x80x9d have an enantiomeric relationship. A person skilled in the art is able to determine the absolute configuration of such compounds using art-known methods such as, for example, X-ray diffraction.
For example, intermediate 2b having the stereochemical descriptor [2S-[2xcex1,4xcex1[A-(R*,S*)]]] denotes the enantiomer having either the[2S-[2xcex1,4xcex1[(R*,S*)]]] or the [2S-[2xcex1,4xcex1[(S*,R*)]]] configuration, and is unambigously characterized by its optical rotation being [xcex1]20D=xe2x88x9217.79xc2x0 (c=49.75 mg/5 ml N,N-dimethylformamide).
The N-oxide forms of the present compounds are meant to comprise the compounds of formula (I) wherein one or several nitrogen atoms are oxidized to the so-called N-oxide.
Whenever used hereinafter, the term xe2x80x9ccompounds of formula (I)xe2x80x9d is meant to also include their N-oxide forms, their pharmaceutically acceptable addition salts, and their stereochemically isomeric forms.
Within the scope of the present invention, xe2x80x94Axe2x80x94Bxe2x80x94 is suitably a radical of formula (b).
D is suitably a radical of formula D1.
X is suitably N.
R1 and R2 suitably are identical, preferably chloro or fluoro. In particular, both R1 and R2 are fluoro.
An interesting group of compounds within the present invention are those compounds of formula (I) wherein L represents a radical of formula (a) 
wherein
Rxe2x80x2 represents amino; mono- or di(C1-6alkyl)amino; aminoC1-6alkyl:
C1-6alkyloxycarbonylamino; benzyloxycarbonylamino; trifuoromethoxycarbonylamino;
1-pyrrolidinyl; 1-piperidinyl; 4-morpholinyl; 1-piperazinyl or 1-piperazinyl substituted with C1-6alkyl, hydroxyC1-6alkyl, aminoC1-6alkyl or C1-6alkylaminoC1-6alkyl;
Rxe2x80x3 represents hydrogen; C1-6alkyl; aryl; C1-6alkyl substituted with aryl, C1-6alkylthio, indolyl, amino, hydroxy, mercapto, aminocarbonyl, carboxyl, guanidinyl, imidazolyl; or
Rxe2x80x2 and Rxe2x80x3 taken together form xe2x80x94CH2xe2x80x94CH2xe2x80x94CH2xe2x80x94NHxe2x80x94; aryl is phenyl or phenyl substituted with hydroxy or halo.
A more interesting group contains those compounds of formula (I) wherein L represents the acyl moiety of one of the following amino acids: 
or those derivatives thereof in which the amino moiety is mono- or disubstituted with C1-6alkyl or mono-substituted with tert-butyloxycarbonyl.
Particularly interesting acyl moieties are those originating from alanine, xcex2-alanine, glycine, leucine, valine, phenylglycine, phenylalanine and their N-tert-butyloxycarbonyl derivative, and N,N-diethylglycine and N,N-diethyl-xcex2-alanine; especially, glycine, xcex2-alanine, L-alanine, L-valine, L-leucine, L-phenylglycine, L-phenylalanine, D-phenylalanine, N-((1,1-dimethylethyl)oxycarbonyl)-xcex2-alanine, N-((1,1-dimethylethyl)oxy-carbonyl)-glycine, N,N-diethyl-glycine, N,N-diethyl-xcex2-alanine, N-((1,1-dimethylethyl)oxy-carbonyl)-L-alanine, N-((1,1-dimethylethyl)oxy-carbonyl)-L-leucine, N-((1,1-dimethylethyl)oxycarbonyl)-L-phenyl-glycine, N-((1,1-dimethylethyl)oxycarbonyl)-L-valine, N-((1,1-dimethylethyl)oxy-carbonyl)-L-phenyl-alanine, N-((1,1-dimethylethyl)oxy-carbonyl)-D-phenyl-alanine.
Particular compounds are those compounds of formula (I) wherein D is a radical of formula D1 wherein X is N and R1 and R2 are both fluoro; and xe2x80x94Axe2x80x94Bxe2x80x94 is a radical of formula (b); and L represents the acyl moiety of leucine, valine, phenylglycine, phenylalanine and their N-tert-butyloxycarbonyl derivative; or L represents the acyl moiety of N,N-diethylglycine.
Other particular compounds are those compounds of formula (I) wherein D, whether it is D1 or D2, has a cis configuration.
Preferred compounds are those compounds wherein D is a radical of formula D1 wherein the substituents on the dioxolane ring have a cis configuration and carbon atom number 2 of the dioxolane ring has an absolute S configuration as depicted hereinbelow. 
Other preferred compounds are those compounds wherein the 1-methylpropyl moiety has a threo configuration, i.e. the two chiral carbons of the 1-methylpropyl moiety (both chiral carbon atoms are marked with an asterisk in the figure hereinbelow) have identical absolute configura-tions, e.g. they both have the R configuration or they both have the S configuration. 
More preferred compounds are the compounds of formula (I) in their enantiomerically pure forms, in particular those compounds of formula (I) wherein the two chiral carbons of the 1-methylpropyl moiety both have the S configuration, and D is a radical of formula D1 wherein the substituents on the dioxolane ring have a cis configuration and carbon atom number 2 of the dioxolane ring has an absolute S configuration, which corresponds to those compounds of formula (I) wherein D is a radical of formula D1 having the [2S-[2xcex1,4xcex1[(R*,R*)]]] configuration.
Most preferred are the compounds;
2-[4-[4-[4-[4-[[2-(2,4-difluorophenyl)-2-(1H-1,2,4-triazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]phenyl]-1-piperazinyl]phenyl]-4,5-dihydro-5-oxo-1H-1,2,4-triazol-1-yl]-1-methylpropyl N,N-diethylglycine;
2-[4-[4-[4-[4-[[2-(2,4-difluorophenyl)-2-(1H-1,2,4-triazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]-phenyl]-1-piperazinyl]-phenyl]-4,5-dihydro-5-oxo-1H-1,2,4-triazol-1-yl]-1-methylpropyl L-phenylalanine;
2-[4-[4-[4-[4-[[2-(2,4-difluorophenyl)-2-(1H-1,2,4-triazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]-phenyl]-1-piperazinyl]-phenyl]-4,5-dihydro-5-oxo-1H-1,2,4-triazol-1-yl]-1-methylpropyl L-leucine;
2-[4-[4-[4-[4-[[2-(2,4-difluorophenyl)-2-(1H-1,2,4-triazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]-phenyl]-1-piperazinyl]-phenyl]-4,5-dihydro-5-oxo-1H-1,2,4-triazol-1-yl]-1-methylpropyl L-valine;
2-[4-[4-[4-[4-[[2-(2,4-difluorophenyl)-2-(1H-1,2,4-triazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]-phenyl]-1-piperazinyl]-phenyl]-4,5-dihydro-5-oxo-1H-1,2,4-triazol-1-yl]-1-methylpropyl L-phenylglycine; the N-oxide forms, the pharmaceutically acceptable addition salts thereof and the stereochemical isomeric forms thereof, especially their [2S-[2xcex1,4xcex1[(R*,R*)]]] form.
The meaning of the variables as used in the following reaction procedures is as defined hereinabove, unless otherwise stated.
The compounds of the present invention may be prepared using art-known esterification methods e.g., those described in xe2x80x9cPrinciples of Peptide Synthesisxe2x80x9d, M. Bodanszky, Springer-Verlag Berlin Heidelberg, 1984. Particular reaction procedures are described hereinbelow.
The compounds of formula (I) may generally be prepared by O-acylation of an inter-mediate alcohol of formula (II) with an acylating reagent of formula (III), wherein W1 is a reactive leaving group such as, halo, azido or an activated acid function, e.g. a halophenyl ester such as a pentachloro- or pentafluorophenyl ester, and is connected to the acyl moiety of L. Said reaction may be performed following art-known acylation procedures, for instance, by stirring the reactants in a reaction-inert solvent, optionally in admixture with a base to pick up the acid that is formed during the reaction. Alternatively, the O-acylation is done by using a suitable coupling reagent such as dicyclohexylcarbodiimide or a functional derivative thereof. 
In this and the following preparations, the reaction products may be isolated from the reaction medium and, if necessary, further purified according to methodologies generally known in the art such as, for example, extraction, crystallization, trituration and chromatography.
The compounds of formula (I) may also be prepared by O-alkylating a phenol of formula (IV) with an alkylating reagent of formula (V), wherein W2 is a reactive leaving group such as halo, or a sulfonyloxy group. Said reaction may be performed by stirring the reactants in a reaction-inert solvent, optionally in admixture with a suitable base to pick up the acid that is formed during the reaction. In the compounds and intermediates mentioned hereinafter the substituents are as defined above, unless otherwise indicated. 
The preparation of intermediates of formula (V), wherein D is a radical of formula D1, has been disclosed in U.S. Pat. No. 4,267,179.
As defined hereinabove, the variable L may also be represented by Lxe2x80x2xe2x80x94NRxRy of which the two moieties, i.e. Lxe2x80x2xe2x80x94andxe2x80x94NRxRy are used in the following reaction scheme. 
The above reaction scheme depicts the preparation of the compounds of formula (I) by O-acylating an intermediate of formula (II) with a reagent of formula (VI), wherein W3 is a reactive leaving group such as halo, and W1 is as defined hereinabove and is connected to the acyl moiety Lxe2x80x2; and subsequently reacting the thus obtained intermediate of formula (VII) with an amine of formula (VIII).
The compounds of formula (I) may also be converted into each other following art-known transformations. For instance, compounds of formula (I) wherein L contains a protected amino moiety may be converted to compounds of formula (I) wherein said amino moiety is unsubstituted, using art-known deprotection procedures, e.g. by reaction with trifluoroacetic acid in an appropriate solvent, e.g. dichloromethane.
The compounds of formula (I) may also be converted to the corresponding N-oxide forms following art-known procedures for converting a trivalent nitrogen into its N-oxide form. Said N-oxidation reaction may generally be carried out by reacting the starting material of formula (I) with an appropriate organic or inorganic peroxide. Appropriate inorganic peroxides comprise, for example, hydrogen peroxide, alkali metal or earth alkaline metal peroxides, e.g. sodium peroxide, potassium peroxide; appropriate organic peroxides may comprise peroxy acids such as, for example, benzenecarboperoxoic acid or halo substituted benzenecarboperoxoic acid, e.g. 3-chlorobenzenecarboperoxoic acid, peroxoalkanoic acids, e.g. peroxoacetic acid, alkylhydroperoxides, e.g. tert-butyl hydroperoxide. Suitable solvents are, for example, water, lower alkanols, e.g. ethanol and the like, hydrocarbons, e.g. toluene, ketones, e.g. 2-butanone, halogenated hydrocarbons, e.g. dichloromethane, and mixtures of such solvents.
Some of the intermediates and starting materials used in the above reaction procedures are commercially available, or may be synthesized according to procedures described elsewhere, e.g. U.S. Pat. No. 4,791,111, U.S. Pat. No. 4,931,444 and U.S. Pat. No. 4,267,179. Some methods of preparing the intermediates of the present invention are described hereinbelow.
For instance, the intermediates of formula (II) may be prepared by O-alkylating a reagent of formula (IX) with an alkylating reagent of formula (V) following O-alkylation procedures described hereinabove for the preparation of compounds of formula (I). 
The intermediates of formula (II) may also be prepared by O-alkylating a reagent of formula (X) with an alkylating reagent of formula (V) following O-alkylation procedures described hereinabove for the preparation of compounds of formula (I), and subsequently reducing the thus formed intermediate of formula (XI). Said reduction may be performed by stirring the intermediate of formula (XI) with a reducing reagent, such as, for example, sodiumborohydride in a reaction-inert solvent, such as, for example, dichloromethane, methanol or mixtures thereof. 
The preparation of intermediates of formula (X) is disclosed in U.S. Pat. No. 4,931,444.
The intermediates of formula (XI) may also be prepared by N-alkylating an intermediate of formula (XII) following art-known N-alkylation procedures with an alkylating reagent of formula (XIII), wherein W4 is an appropriate leaving group, e.g. halo. 
Pure stereochemically isomeric forms of the compounds and the intermediates of this invention may be obtained by the application of art-known procedures. Diastereomers may be separated by physical separation methods such as selective crystallization and chromatographic techniques, e.g. liquid chromatography. Enantiomers may be separated from each other by the selective crystallization of their diastereomeric salts with optically active acids. Alternatively, enantiomers may be separated by chromatographic techniques using chiral stationary phases. Said pure stereochemically isomeric forms may also be derived from the corresponding pure stereochemically isomeric forms of the appropriate starting materials, provided that the reaction occurs stereoselectively or stereospecifically. Preferably if a specific stereoisomer is desired, said compound will be synthesized by stereoselective or stereospecific methods of preparation. These methods will advantageously employ enantiomerically pure starting materials. Stereochemically isomeric forms of the compounds of formula (I) are obviously intended to be included within the scope of the invention.
As stated hereinabove, the enantiomerically pure forms of the compounds of formula (I) form a preferred group of compounds. It is therefore that the enantiomerically pure forms of the intermediates of formula (II), their N-oxide forms and their addition salt forms are particularly useful in the preparation of enantiomerically pure compounds of formula (I). Also enantiomeric mixtures and diastereomeric mixtures of intermediates of formula (II) are useful in the preparation of compounds of formula (I) with the corresponding configuration. Said enantiomerically pure forms and also the enantiomeric and diastereomeric mixtures of the intermediates of formula (II) are deemed novel.
4-[4-[4-[4-[[2-(2,4-difluorophenyl)-2-(1H-1,2,4-triazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]phenyl]-1-piperazinyl]phenyl]-2,4-dihydro-2-(2-hydroxy-1-methylpropyl) -3H-1,2,4-triazol-3-one in its [2S-[2xcex1,4xcex1[(R*,R*)]]] enantiomerically pure form and the corresponding 2,4-dichlorophenyl analogue are particularly preferred intermediates of formula (II).
In particular, the [2S-[2xcex1,4xcex1[(R*,R*)]]] pure enantiomeric form of intermediates of formula (II) can be prepared by reacting the corresponding enantiomerically pure form of intermediate (IX), i.e. the [Sxe2x80x94(R*,R*)] form, being represented by formula (IX-a), with the corresponding enantiomerically pure form of intermediate (V), i.e. the [2S-(2xcex1,4xcex1)] form, being represented by (V-a), according to the reaction procedure as described above.
The stereoselective synthesis of intermediate (IX-a) starting from intermediate (X) can be performed as depicted in scheme 1. 
Suitable stereoselective reduction conditions include the use of K-selectride in a suitable solvent such as, for example, dimethylacetamide or tetrahydrofuran; the use of sodiumborohydride optionally in combination with CeCl3.7H2O, ZnCl2 or CaCl2.2H2O in a suitable solvent such as, for example, dimethylacetamide, dimethylformamide, methanol or tetrahydrofuran. Said reduction conditions favour the threo form of the 2-hydroxy-1-methylpropyl moiety, i.e. the form where the two asymmetric carbon atoms have identical absolute configuration. Recrystallisation of the obtained mixture after stereoselective reduction may even further improve the ratio threo/erythro in favor of the threo form. The desired [Sxe2x80x94(R*,R*)] form can then be isolated chromatographically using a chiral stationary phase such as, for example, Chiralpak AD (amylose 3,5 dimethylphenyl carbamate) purchased from Daicel Chemical Industries, Ltd, in Japan.
The alkoxyphenyl derivatives of the intermediates of formula (IX-a) may be prepared according to the same reaction procedures as in scheme 1.
An alternative way to prepare intermediates of formula (IX-a), or the alkoxyphenyl analogues thereof, is as depicted in scheme 2. 
The reaction of an intermediate of formula (XIV) with (4R-trans)-4,5-dimethyl-2,2-dioxide-1,3,2-dioxathiolane may be performed in a suitable solvent, preferably a polar aprotic solvent such as, for example, dimethylacetamide or N,N-dimethylformamide, and in the presence of a base such as, for example, potassium tert-butanolate, potassium hydroxide or potassium hydride. Subsequently, an acid such as, sulfuric acid, may be added to the reaction mixture, thus obtaining an intermediate of formula (XV-b) whereby the 2-hydroxy-1-methylpropyl moiety has the erythro form. Then, the carbon atom bearing the alcohol function of said 2-hydroxy-1-methylpropyl moiety is epimerized, preferably 100% inverted, thus obtaining intermediate (XV-a) whereby the 2-hydroxy-1-methylpropyl moiety has the threo form. Two pathways are convenient.
A first pathway involves the transformation of the alcohol function into a suitable leaving group Oxe2x80x94LG by, for instance, derivatizing the hydroxy group with an organic acid such as, for example, a carboxylic acid, e.g. acetic acid or 4-nitrobenzoic acid; or a sulfonic acid, e.g. p-toluenesulfonic acid or methanesulfonic acid; thus obtaining an intermediate of formula (XVI). The carbon atom bearing the leaving group in said intermediate (XVI) may subsequently be epimerized, preferably 100% inverted, by a SN2-type reaction with a suitable nucleophilic reagent such as, for example, a alcoholate, e.g. a benzyloxy group; an hydroxy salt of an alkali metal, e.g. sodiumhydroxide or potassium hydroxide; an acetate, e.g. sodium acetate. Said reaction is performed in a suitable solvent, preferably a polar aprotic solvent such as, for example, dimethylacetamide, N-methylpyrrolidinone, dimethylimidazolidinone or sulfolane. In case an alcoholate or an acetate is used in the SN2 reaction, the thus obtained intermediate may be deprotected using art-known deprotection techniques, thus obtaining an alcohol intermediate of formula (XV-a).
An alternative pathway for inverting the stereochemistry of the carbon atom bearing the alcohol function is the use of the Mitsunobu reaction. The alcohol function of an intermediate of formula (XV-b) is activated with diisopropyl azodicarboxylate or a functional derivative thereof such as diethyl azodicarboxylate, in the presence of triphenylphosphine, and in a polar aprotic solvent such as, for example, dimethylacetamide or dimethylformamide. The thus obtained activated alcohol is subsequently reacted with a carboxylic acid such as, for example, 4-nitrobenzoic acid, acetic acid, monochloroacetic acid. The thus obtained ester whereby the 2-hydroxy-1-methylpropyl moiety has been transformed to the threo form may subsequently be hydrolized using art-known hydrolysis techniques, thus obtaining an intermediate of formula (XV-a).
Finally, the alkoxyphenyl moiety of the intermediates of formula (XV-a) may be transformed to the phenol moiety using for instance, bromic acid in acetic acid in the presence of sodium thiosulfate, thus obtaining an intermediate of formula (IX-a).
Suitable alternatives for (4R-trans)-4,5-dimethyl-2,2-dioxide-1,3,2-dioxathiolane include the following enantiomerically pure intermediates: 
wherein LG is a leaving group such as, for example, p-toluenesulfonyl.
The intermediates of formula (IX-b), whereby the 2-hydroxy-1-methylpropyl moiety has the [Rxe2x80x94(R*,R*)] form, may be prepared using the same reaction pathways as depicted in scheme 2 but replacing (4R-trans)-4,5-dimethyl-2,2-dioxide-1,3,2-dioxathiolane with its enantiomer (4S-trans)-4,5-dimethyl-2,2-dioxide-1,3,2-dioxathiolane.
Alternatively to the reaction pathway in scheme 2, an intermediate of formula (XIV) may be directly coupled with an enantiomerically pure intermediate such as [Rxe2x80x94(R*,S*)]-3-bromo-2-butanol 4-nitrobenzoate or a functional derivative thereof, thus immediately obtaining an intermediate of formula (XV-a).
Interestingly, particular pure enantiomeric forms of the intermediates of formula (IV) may be synthesized using the Mitsunobu pathway in scheme 2 whereby the carboxylic acid, used in the reaction with the activated alcohol of formula (XV-b), is replaced with a protected amino acid. Optionally, the amino acid may be deprotected using art-known techniques.
The compounds of formula (I), the pharmaceutically acceptable addition salts and the stereochemically isomeric forms thereof are useful agents for combating fungi in vivo. Moreover, the solubility profile in aqueous solutions of the compounds of formula (I) makes them suitable for intravenous administration. The present compounds are found to be active against a wide variety of fungi, such as Candida spp., e.g. Candida albicans, Candida glabrata, Candida krusei, Candida parapsilosis, Candida kefyr, Candida tropicalis; Aspergillus spp., e.g. Aspergillus fumigatus, Aspergillus niger, Aspergillus flavus; Cryptococcus neoformans; Sporothrix schenckii; Fonsecaea spp.; Epidermophyton floccosum; Microsporum canis; Trichophyton spp.; Fusarium spp.; and several dermatiaceous hyphomycetes.
Also, the pure enantiomers, the enantiomeric mixtures and the diastereomeric mixtures of the intermediates of formula (II) are antimycotics having a favourable pharmacological profile with respect to antifungal activity and adverse effects.
The chemical stability of some of the compounds of formula (I) has been determined as is shown in the experimental part hereinafter. Experiments show that metabolic degradation of the present compounds to the intermediates of formula (II) is organ specific and does not occur readily. Further, in vitro experiments indicate that the compounds of formula (I) have an improved intrinsic inhibitory capacity on fungal growth in for instance Candida albicans when compared to the intermediates of formula (II), of which the antifungal activity is taught in U.S. Pat. No. 4,791,111. Said in vitro experiments include the determination of the fungal susceptibility of the present compounds as described in the pharmacological example hereinafter. Other in vitro experiments such as the determination of the effects of the present compounds on the sterol synthesis in, for instance, Candida albicans, demonstrate their antifungal potency. Also in vivo experiments in several mouse, guinea-pig and rat models show that, after both oral and intravenous administration, the present compounds are potent antifungals.
The compounds of the present invention also have a good oral availability.
In view of the utility of the compounds of formula (I), there is provided a method of treating warm-blooded animals, including humans, suffering from fungal infections. Said method comprises the systemic or topical administration of an effective amount of a compound of formula (I), a N-oxide form, a pharmaceutically acceptable addition salt or a possible stereoisomeric form thereof, to warm-blooded animals, including humans. Hence, compounds of formula (I) are provided for use as a medicine, in particular, the use of a compound of formula (I) in the manufacture of a medicament useful in treating fungal infections is provided.
The present invention also provides compositions for treating or preventing fungal infections comprising a therapeutically effective amount of a compound of formula (I) and a pharmaceutically acceptable carrier or diluent.
In view of their useful pharmacological properties, the subject compounds may be formulated into various pharmaceutical forms for administration purposes. To prepare the pharmaceutical compositions of this invention, a therapeutically effective amount of a particular compound, in base or addition salt form, as the active ingredient is combined in intimate admixture with a pharmaceutically acceptable carrier, which carrier may take a wide variety of forms depending on the form of preparation desired for administration. These pharmaceutical compositions are desirably in unitary dosage form suitable, preferably, for administration orally, rectally, topically, percutaneously, or by parenteral injection. For example, in preparing the compositions in oral dosage form, any of the usual pharmaceutical media may be employed, such as, for example, water, glycols, oils, alcohols and the like in the case of oral liquid preparations such as suspensions, syrups, elixirs and solutions: or solid carriers such as starches, sugars, kaolin, lubricants, binders, disintegrating agents and the like in the case of powders, pills, capsules and tablets. Because of their ease in administration, tablets and capsules represent the most advantageous oral dosage unit form, in which case solid pharmaceutical carriers are obviously employed. As appropriate compositions for topical application there may be cited all compositions usually employed for topically administering drugs e.g. creams, gellies, dressings, shampoos, tinctures, pastes, ointments, salves, powders and the like. For parenteral compositions, the carrier will usually comprise sterile water, at least in large part, though other ingredients, to aid solubility for example, e.g. cyclodextrins, may be included. Injectable solutions, for example, may be prepared in which the carrier comprises saline solution, glucose solution or a mixture of saline and glucose solution. Injectable suspensions may also be prepared in which case appropriate liquid carriers, suspending agents and the like may be employed. In the compositions suitable for percutaneous administration, the carrier optionally comprises a penetration enhancing agent and/or a suitable wetting agent, optionally combined with suitable additives of any nature in minor proportions, which additives do not cause a significant deleterious effect to the skin. Said additives may facilitate the administration to the skin and/or may be helpful for preparing the desired compositions. These compositions may be administered in various ways, e.g., as a transdermal patch, as a spot-on, as an ointment. For parenteral compositions, the carrier will usually comprise sterile water, at least in large part. Injectable solutions, for example, may be prepared in which the carrier comprises saline solution, glucose solution or a mixture of saline and glucose solution. Injectable suspensions may also be prepared in which case appropriate liquid carriers, suspending agents and the like may be employed. For parenteral compositions, other ingredients, to aid solubility for example, e.g. cyclodextrins, may be included. Appropriate cyclodextrins are xcex1-, xcex2-, xcex3-cyclodextrins or ethers and mixed ethers thereof wherein one or more of the hydroxy groups of the anhydroglucose units of the cyclodextrin are substituted with C1-6alkyl, particularly methyl, ethyl or isopropyl, e.g. randomly methylated xcex2-CD; hydroxyC1-6alkyl, particularly hydroxyethyl, hydroxypropyl or hydroxybutyl; carboxyC1-6alkyl, particularly carboxymethyl or carboxyethyl; C1-6alkylcarbonyl, particularly acetyl. Especially noteworthy as complexants and/or solubilizers are xcex2-CD, randomly methylated xcex2-CD, 2,6-dimethyl-xcex2-CD, 2-hydroxyethyl-xcex2-CD, 2-hydroxyethyl-xcex3-CD, 2-hydroxypropyl-xcex3-CD and (2-carboxymethoxy)propyl-xcex2-CD, and in particular 2-hydroxypropyl-xcex2-CD (2-HP-xcex2-CD).
The term mixed ether denotes cyclodextrin derivatives wherein at least two cyclodextrin hydroxy groups are etherified with different groups such as, for example, hydroxy-propyl and hydroxyethyl.
The average molar substitution (M.S.) is used as a measure of the average number of moles of alkoxy units per mole of anhydroglucose. The average substitution degree (D.S.) refers to the average number of substituted hydroxyls per anhydroglucose unit. The M.S. and D.S. value can be determined by various analytical techniques such as nuclear magnetic resonance (NMR), mass spectrometry (MS) and infrared spectroscopy (IR). Depending on the technique used, slightly different values may be obtained for one given cyclodextrin derivative. Preferably, as measured by mass spectrometry, the M.S. ranges from 0.125 to 10 and the D.S. ranges from 0.125 to 3.
It is especially advantageous to formulate the aforementioned pharmaceutical compositions in dosage unit form for ease of administration and uniformity of dosage. Dosage unit form as used in the specification and claims herein refers to physically discrete units suitable as unitary dosages, each unit containing a predetermined quantity of active ingredient calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier. Examples of such dosage unit forms are tablets (including scored or coated tablets), capsules, pills, powder packets, wafers, injectable solutions or suspensions, teaspoonfuls, tablespoonfuls and the like, and segregated multiples thereof.
Those of skill in treating warm-blooded animals suffering from diseases caused by fungi could easily determine the therapeutically effective daily amount from the test results given herein. In general, it is contemplated that a therapeutically effective daily amount would be from 0.05 mg/kg to 20 mg/kg body weight.
Experimental Part
Hereinafter, xe2x80x9cDMFxe2x80x9d is defined as N,N-dimethylformamide, xe2x80x9cMIKxe2x80x9d is defined as methylisobutylketone, xe2x80x9cDIPExe2x80x9d is defined as diisopropylether.
A. Preparation of the Intermediates